PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                           No. 02-4551
JOHN L. BROWER,
              Defendant-Appellant.
                                       
            Appeal from the United States District Court
       for the Middle District of North Carolina, at Durham.
                William L. Osteen, District Judge.
                            (CR-02-21)

                      Argued: May 7, 2003

                      Decided: July 9, 2003

  Before LUTTIG, WILLIAMS, and TRAXLER, Circuit Judges.



Affirmed by published opinion. Judge Williams wrote the opinion, in
which Judge Luttig and Judge Traxler joined.


                           COUNSEL

ARGUED: Gregory Davis, Assistant Federal Public Defender,
Greensboro, North Carolina, for Appellant. Sandra Jane Hairston,
Assistant United States Attorney, Greensboro, North Carolina, for
Appellee. ON BRIEF: Louis C. Allen, III, Federal Public Defender,
Greensboro, North Carolina, for Appellant. Anna Mills Wagoner,
United States Attorney, Greensboro, North Carolina, for Appellee.
2                     UNITED STATES v. BROWER
                             OPINION

WILLIAMS, Circuit Judge:

   John L. Houston Brower appeals his conviction for knowingly and
intentionally distributing more than 50 grams of a substance contain-
ing cocaine base. Brower argues that the district court erred by
instructing the jury that the Government did not have to prove that he
knew the exact nature of the substance he distributed. For the reasons
set forth below, we affirm.

                                  I.

   On January 29, 2002, a federal grand jury in the United States Dis-
trict Court for the Middle District of North Carolina indicted Brower
for knowingly and intentionally distributing 68.8 grams of a substance
containing a detectable amount of cocaine base in violation of 21
U.S.C.A. § 841(a)(1) (West 1999). Brower pleaded not guilty and was
tried by a jury. After the close of evidence, the district court, over
Brower’s objections, instructed the jury that

    [a]lthough the Government must prove the Defendant knew
    he distributed a controlled substance, the Government does
    not have to prove the Defendant knew the actual nature of
    the substance he distributed. It is enough that the Govern-
    ment proves the Defendant knew he distributed some kind
    of controlled substance.

(J.A. at 163-64.)

   On April 9, 2002, Brower was found guilty of distributing more
than 50 grams of a substance containing a detectable amount of
cocaine base. On June 21, 2002, Brower was sentenced to life in
prison under 21 U.S.C.A. § 841(b)(1)(A)(iii). Brower filed a timely
notice of appeal.

                                 II.

   We consider de novo whether a jury was properly instructed on the
statutory elements of an offense. United States v. Horton, 321 F.3d
                        UNITED STATES v. BROWER                           3
476, 479 (4th Cir. 2003). Section 841(a) provides, in pertinent part:
"[I]t shall be unlawful for any person knowingly or intentionally —
(1) to . . . distribute . . . a controlled substance." 21 U.S.C.A.
§ 841(a)(1). Section 841(b)(1)(A)(iii) permits an enhanced sentence
for a drug offense under § 841(a) involving "50 grams or more of a
mixture or substance described in clause (ii) which contains cocaine
base." 21 U.S.C.A. § 841(b)(1)(A)(iii). Brower argues that under
Fourth Circuit caselaw and the Supreme Court’s opinion in Apprendi
v. New Jersey, 

(2000), this statutory language requires
the Government to prove that he knew that he was distributing the
controlled substance that was alleged in the indictment, that is,
cocaine base. Thus, according to Brower, the district court’s instruc-
tion to the jury that the Government need only prove that he knew
that he was distributing some kind of controlled substance was erro-
neous.

   We held, prior to Apprendi, that "[i]n order to secure a conviction
under [§ 841(a)(1)] the government must prove beyond a reasonable
doubt that (1) defendant knowingly or intentionally distributed the
controlled substance alleged in the indictment, and (2) at the time of
such distribution the defendant knew that the substance distributed
was a controlled substance under the law." United States v. Tran
Trong Cuong, 

, 1137 (4th Cir. 1994). The district court’s
instruction, therefore, is not inconsistent with Fourth Circuit caselaw.1
  1
    Brower, however, insists that this court’s case law in fact requires the
government to prove that a defendant knew which controlled substance
he was distributing. In support of this argument, Brower points to United
States v. Burgos, 

(4th Cir. 1996) (en banc), which stated that
"[t]he elements necessary to prove a conviction for possession with
intent to distribute cocaine base are: (1) possession of the cocaine base;
(2) knowledge of this possession; and (3) intention to distribute the
cocaine base." 

(emphasis added). This articulation of the ele-
ments of a section 841 charge was made in the context of a challenge to
the sufficiency of the government’s evidence that the defendant pos-
sessed the drugs. There was no challenge to the jury instructions in Bur-
gos, and the issue before this court today was in no way implicated by
any of the issues before the Burgos court. Under these circumstances, the
Burgos court’s shorthand discussion of the elements of a section 841
charge cannot be understood to have worked a change, sub silentio, in
the long-standing rule that the government need only prove that the
defendant knew he was distributing some controlled substance.
4                      UNITED STATES v. BROWER
   The issue, then, is whether Apprendi changed the Government’s
mens rea burden with regard to the particular controlled substance
involved in the offense. The Government’s mens rea burden is
defined under § 841(a), which makes it an offense to "knowingly or
intentionally" distribute a controlled substance. The Court in
Apprendi held that "any fact that increases the penalty for a crime
beyond the prescribed statutory maximum must be submitted to a
jury, and proved beyond a reasonable 

. The
penalty for a drug offense under § 841(a) can be increased under
§ 841(b) where the offense "involv[ed]" specific amounts of specific
drugs. 21 U.S.C.A. § 841(b)(1)(A). But there is no requirement that
to justify imposition of an enhanced sentence the Government prove
that the defendant knew the specific amount or specific type of drug
involved. Rather, an enhanced sentence under § 841(b) only requires
the Government to prove beyond a reasonable doubt that the drug
offense involved the amount of the specific drug alleged in the indict-
ment. 

Simply stated, the defendant’s knowledge with
regard to the exact nature, or for that matter the exact amount, of a
controlled substance is not a fact that increases the penalty under
§ 841(b). The holding in Apprendi, therefore, does not require the
Government to prove that Brower knew that he was distributing a
substance containing cocaine base and, accordingly, the district court
did not err by instructing the jury that the Government needed only
to prove that Brower knew that he was distributing a controlled sub-
stance. See United States v. Barbosa, 

, 458 (3rd Cir.
2001), cert. denied, __ U.S. __, 

(2002) ("[T]he struc-
ture and plain text of § 841 affords no support for a requirement that
the Government must prove more than the defendant’s knowledge
that he was trafficking in a controlled substance."); see also United
States v. Villarce, 

, 439 (6th Cir. 2003) (listing cases).2

    2
   For the first time in his reply brief, Brower raises a claim regarding
the consistency of the jury instructions. Because it was not included in
his opening brief, we consider it waived. See Carter v. Lee, 

, 252 n.11 (4th Cir. 2002) (contentions not raised in the opening brief
generally considered waived).
                      UNITED STATES v. BROWER                      5
                                III.

   For the foregoing reasons, we affirm Brower’s conviction for
knowingly and intentionally distributing more than 50 grams of a sub-
stance containing cocaine base.

                                                        AFFIRMED